In recent years, pulsed lasers with high repetition rate have been widely used in many fields, such as optical frequency measurement, high-speed electro-optic sampling, laser ranging, and high-average-power ultrafast lasers. Therefore, it has important application values. For the conventional fiber lasers, it is easier to realize a pulse sequence from kHz to hundreds of MHz. However, for the reason the fiber lasers are limited to its gain fiber length, other inner devices and the length of tail fiber, it is difficult to increase the repetition rate.
This invention puts forward a novel method to increase pulsed laser repetition rate by using a 2*2 type, splitting ratio 1:1 coupler (hereinafter written as 2*2, 1:1 coupler) and controlling the optical path difference to realize a low-loss mutual coupling of laser pulses.